Stowable air scoop

ABSTRACT

A foldable ram air scoop for gathering and channeling external air into a secondary thrust chamber, or afterburner, of an airaugmented thrust propelled missile is provided. The scoop is deployable prior to launch, being foldable against the missile body while stowed within a volume restricted storage magazine. The present air scoop essentially comprises a two-stage folding mechanism which compactly holds the scoop body against the missile, controllably deploys the scoop to a desired configuration, and positively locks the scoop in the proper position.

United States Patent Polk, Jr.

[451 May 2,1972

[54] STOWABLE AIR SCOOP [72] Inventor: Albert S. Polk, Jr., Baltimore,Md.

[73] Assignee: The Unlted States 01 America as represented by theSecretary of the Navy [22] Filed: Oct. 7, 1970 [21] Appl.No.: 78,771

[52] U.S.Cl. ..60/269, 60/245, 137/l5.l,

244/53 B [5.1]- Int. CL; ..F02k 9/06 [58] Field of Search ..60/270, 269,245, 244, 356 L,

60/356 PP; 137/l5.l, 15.2; 244/327; 107/493, 49.4; 244/53 B, 129 D [56]References Cited UNlTED STATES PATENTS v 3,347,496 10/1967 Opfer..60/269 3,482,403 12/1969 Polk ..60/270 2,995,893 8/1961 Morris et a1.i ..60/244 3,059,878 10/1962 Kerry et a1 .244/53 8 3,173,249 3/1965Wiggins ..60/245 3,027,711 4/1962 Rae..., ..l37/15.l PrimaryExaminer-Douglas Hart Assistant Examiner-Warren Olsen Altorney--R. S.Sciascia and .1. A. Cooke [57] ABSTRACT A foldable ram air scoop forgathering and channeling external air into a secondary thrust chamber,or afterburner, of an air-augmented thrust propelled missile isprovided. The scoop is deployable prior to launch, being foldableagainst the missile body while stowed within a volume restricted storagemagazine. The present air scoop essentially comprises a twostage foldingmechanism which compactly holds the scoop body against the missile,controllably deploys the scoop to a desired configuration, andpositively locks the scoop in the proper position.

l0 10 Drawing Figures PATENTEDMAY ZIQTZ 3,659,424 SHEET 10F 5 INVENTOR.

v ALBERT s. POLK JR.

PATENTEBMAY 2 I972 3, 659.424

SHEET 2 BF 5 INVENTOR. ALBERT S. POLK. JR.

PATENTEDMAY 2 I972 SHEET 3 OF 5 INVENTOR. ALBERT S. POLK JR.

PATENTEUMAY 2 I972 SHEET 4 BF 5 INVENTOR. ALBERT s. POLK JR.

PATENTEDMAY 2 I972 SHEET 5 OF 5 INVENTOR. ALBERT S. POLK JR.

m UPK arr- BACKGROUND AND'SUMMARY OF THE INVENTION Air capture andducting mechanisms for supplying external air to a ramjet engine havepreviously been used. Generally, the air supplied from the environmentof the vehicle being propelled by the ramjet engine burns with fuel in acombustion chamber used previously as a fuel chamber for booster burn.The air scoop itself must be large enough to accommodate a desiredvolume of air, yet must have sufiicient structural integrity towithstand the high loading imposed on the relatively non-aerodynamicprojection extending from the aerodynamic body surface of the vehicle.Often it is required that these airbreathing missiles be packagedwithinand often launched from a volume restricted chamber. Presently,thrust augmentation development is primarily directed toward achievementof greater thrust per unit of either launcher volume, magazine storagevolume, or both. An integral rocket-ramjet vehicle which necessitatesthe intake of large quantities of air for internal combustion providesone solution to the present problem. Although useful in otherapplications and missile configurations, the invention is convenientlyapplied to the integral rocket-ramjet vehicle. This vehicle is launchedand accelerated by a solid fuel booster having a fuel chamber which,after burnout and some parts jettison, becomes a combustion chamber forfuel supplied from a liquid fuel chamber. Air scoops structuredaccording to the present invention are disposed on the external surfaceof the vehicle body substantially along that portion covering the liquidfuel chamber. In order to be stowable within a volume restricted storagemagazine, the air scoops must be retractable against and/or within thevehicle body. On exit from the storage magazine and prior to launch, theair scoops are deployed in a desired configuration and, after solid fuelburnout, gather and channel external air through ducts communicatinginto the chamber which now functions as a combustion chamber. Therefore,the principal object of the present invention is to provide a foldableair scoop which is readily deployable from a retracted position to anoptimum extended position and which, on assumption of such extendedposition, positively locks in place.

Use of the present air scoop mechanism is not limited to the integralrocket-ramjet briefly described above. For example, an air-augmentedafterbuming combustion engine may conveniently employ the invention tointroduce extemallygathered oxidizing air into a secondary combustionchamber for more complete oxidation of fuel-rich exhaust gases exiting aprimary combustion chamber. In such instance, the fuelrich, partiallyunoxidized gases entering the secondary combustion, or afterbuming,chamber are oxidized by the air and subsequently ejected from thesecondary combustion chamber with increased specific impulse. Ingeneral, the invention is useful in any known situation requiringexternal gathering and channeling of air into a connection chamber foroxidative reaction therein.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of anintegral rocket-ramjet missile employing the foldable air scoopmechanism of the present invention, said mechanism being shown extended;

FIG. 2 is an exploded perspective, in partial section, of the air scoopand associated structure within the missile body;

FIG. 2a is an enlarged detail side elevation of the stop mechanism forthe scoop body employed;

FIG. 2b is an enlarged detail perspective, partly in section, showingone of the locking elements for the scoop body, together with itsassociated spring and groove;

FIG. 3 is an enlarged detail section of a portion of the integralrocket-ramjet missile and showing the air scoop in its stowedconfiguration;

FIG. 4 is a view similar to FIG. 3 but showing the scoop in erectedflight configuration;

FIG. 5 is'a detail perspective of the locking mechanism for securing thescoop in extended position;

-- FIG. 6 is a top plan view of the ramp employed;

FIG. 7 is a side elevation of the ramp shown in FIG. 6; and FIG. 8 is atransverse section on the line 88 of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention is best describedin an operative environment aboard a particular missile with which theinvention has utility. Such a missile is shown generally at 10 in FIG.I. The missile 10 is an airbreathing two-stage vehicle, launched andaccelerated by an integral solid booster section 12, having a fuelchamber 14 which, on solid fuel burnout, becomes a combustion chamberfor sustained ramjet flight. A liquid fuel chamber 16 disposedimmediately forward of the chamber 14 provides fuel for ramjet flight,while air scoops l8 constructed according to the present inventioncapture external air and direct said air into the chamber 14 forcombustion of the incoming liquid fuel.

The particular advantage of the present air scoops l8 derives from thenecessity of folding said scoops into a lowprofile storageconfiguration. Often, missiles are stowed prior to launch in storagemagazines offering limited volume. In order to stow the missile 10within the most efficient storage volume, external missile appendages,such as fins and said air scoops, must be made to be retractable againstthe body of the missile. Thus, when the missile 10 is removed from astorage magazine and while it is being readied for launch, the airscoops 18 are deployed in flight positions, in a manner to be describedhereinafter. If the missile is not launched and is to be re-stored, theair scoops 18 are retracted to their stowed positions.

Referring to FIGS. 1 and 2, the several component parts of each scoop 18are shown. The missile 10 is seen to be fitted with two of the scoops18, one each on diametrically opposite sides of said missile and on themissile body substantially between the chambers 14 and 16. Each scoop 18mainly comprises a leading edge element 22, a scoop body 24, and a ramp26, these components being shown in an exploded view in FIG. 2 so thatthe scoop may be more easily described and understood. The leading edgeelement 22 is hinged to the scoop body 24 by a hinge pin 28. This hingedassembly substantially overlies an air inlet 30 which is defined by amissile bodyextension 32, a stationary inlet wall 34, a blowout door 36,and portions of the body of the missile. The leading edge element 22consists of an essentially rectangular plate 38 which tapers inthickness to an edge 39.

Guides 40 extend angularly downwardly from the rear of the plate 38 ateach side thereof and, when the scoop is in the stowed position, fitinto sheaths 42 formed in the body of the missile 10 on either side ofand immediately below the inlet wall 34. The guides 40 each have acamming surface 44 of rounded contour which communicates with an openended slot 46. The guides 40 terminate in pointed end portions 48 which,at full scoop deployment, extend partially into the sheaths 42.

Referring also to FIG. 3, the ramp 26 is connected by a hinge pin 50 toa top wall 52 of the fuel chamber 16 and is shaped to maximize fuelstorage volume. The ramp 26 consists of a forward portion 54 which isrelatively gently inclined upwardly and a rear portion 56 which isinclined relatively sharply downwardly, the portions 54 and 56 mergingat 55. As best seen in FIGS. 2, 4 and 7, the under side of the rearportion 56 of the ramp 26 is provided with a stop 57 which has a groove58 and a lip 59, the stop 57 extending laterally a short distance beyondthe side walls of the ramp 26. A leaf spring 60, fastened to the underside of the ramp 26, bears against the top wall 52 to bias said rampupwardly when externally applied forces which tend to hold the ramp downare lessened. In the stowed position shown in FIG. 3, the front surfaceportion 54 of the ramp 26 is seen to lie substantially parallel to thebody of the missile 10.

The scoop body 24, shown best in FIG. 2, performs the major portion ofthe air-gathering function of the air scoop 18. The body 24 consists ofan inverted U-shape, rectangular body plate 62 having two side members63, the body acting as an air-collecting chamber. The side members 63gradually increase in height from the hinged connection of the body 24with the leading edge element 22, and at such an angle that the upperedges of the guides 40 of the element 22 will fit flush against thelower edges of said members. The side members 63 are cut away at 64 andterminate in tapered edge portions 65. Formed in each of the sidemembers 63 near its outer end is an opening 66. The scoop body 24 liessubstantially parallel to the missile when the scoop 18 is in theretracted, or stowed, configuration shown in FIG. 3. In the flightconfiguration, shown in FIG. 4, the scoop body 24 is angularly disposedto the missile 10, the sliding edge portions 65 of the side members 63engaging the body of the missile.

As can be seen in FIGS. 2b, 4, and 5, the scoop body 24 is slidable inexternal tracks 68 which have open longitudinal grooves 69 in theopposite walls thereof. Each groove 69 terminates at its forward end ina circular locking port 70 of a diameter greater than the width of saidgroove, said port 70 extending through said track. Spring-loaded lockingdiscs 71 are received within the circular locking ports 70, as will beexplained hereinbelow. The disc 71 has a circular base 72 and a raisedgenerally rectangular locking element 73 thereon. The locking element 73extends diametrically of the base and is formed with a slot 74 in whichis secured the forward end of a leaf spring 75. As best seen in FIG. 5,the rear end portion of the spring 75 bears against the upper wall ofthe groove 69. The base 72 of each locking disc 71 fits into one 'of theopenings 66 on each side of the scoop body 24. The locking elements 73extend from the base 72 and slide in the grooves 69 in the externaltracks 68. The scoop body 24 is thus mounted for sliding movement alonga fixed path. Movement of the body 24 to a forward, erect position, suchas is shown in FIG. 4, causes the locking elements 73 of the discs 71 toexit the grooves 69 and extend into the circular locking ports 70. Thelocking discs 71 are caused to rock on release of the locking elementsfrom the grooves 69, by the action of the springs 75, to such positionsthat said locking elements will be mis-aligned with respect to thegrooves. Thus, the discs and locking elements prevent the scoop body 24from sliding alt to its retracted configuration.

In FIG. 3, the air scoop 18 is seen in a low-profile, retractedposition. The leading edge element 22, scoop body 24, and ramp 26 areseen to lie substantially parallel to and against the body of themissile 10. The ramp 26 is held downwardly by the camming action of theforward portions of the guides 40. The guides 40 of the edge element 22are substantially received within the sheaths 42. The scoop body 24 liessubstantially flat against the missile, the locking elements 73 of thelocking discs 71 engaging the grooves 69 of the tracks 68 at the pointsof greatest distance from the circular locking ports 70, i.e., near theouter ends of the grooves.

Erection of each of the air scoop 18 is achieved by an actuator (notshown), such as a pneumatic jack located on the body of the missile. Theactuator exerts force on the aft end of the scoop body 24 to move thescoop 18 into the deployed configuration shown in FIG. 4. Deployment ofthe scoop 18 substantially involves sliding the scoop body 24 forwardly,the sliding edge portions 65 of the side members 63 slidably engagingthe body surface of the missile 10. Force is thereby exerted on theleading edge element 22. Thescoop body 24 is forced outwardly from themissile body by the camming action of the guides 40 on a rolled portion76 located on the stop 57 on the ramp 26. The locking discs 71 in theopenings 66 in the scoop body 24 rotate to allow said body to moveforwardly and outwardly and maintain sliding alignment of the lockingelements 73 of said discs 71 within the grooves 69 in the tracks 68. Asthe scoop body 24 slides forwardly and outwardly, the leading edgeelement 22 also moves forwardly and outwardly as the guides 40 are drawnfrom the sheaths 42. However, due to the angle at which the sheaths 42are disposed. in the body of the missile, the body plate 62 of theleading edge element 22 maintains substantially parallel alignment withthe missile body by partially rotating on the hinge pin 28. Continuingforward movement of the scoop body 24 eventually brings the rear edgesof the guides 40 into contact with said scoop body, thus formingcontinuous side walls for the air scoop 18.

As the scoop body 24 reaches the point of maximum forward displacement,the camming surfaces 44 on the guides 40 allow the ramp 26 to be biasedoutwardly by the spring 60. As the ramp 26 moves outwardly about thehinge pin 50, the guides 40 engage the stop 57 with the rolled portion76 in the slots 46. The interconnection between the ramp 26 and theguides 40 of the leading edge element 22 provides, along with thelocking discs 71 which look into the circular locking ports 70substantially simultaneously with the occurrence of the interlockingjust described, positive locking of the air scoop 18 in an erect, airscooping position. In this erect position, the rear portion 56 of theramp 26 is seen to align with the inlet wall 34.

I claim:

1. In an aerial vehicle having a combustion chamber, an air scoopcomprising; i

an inlet wall,

a movable ramp mounted to cooperate with the inlet wall,

a scoop body,

means slidably connecting the scoop body to the vehicle,

said air scoop being movable from an inoperative position lying adjacentthe vehicle to an operative position extending from the vehicle,

said scoop body, said ramp and said inlet wall cooperating to define anair inlet for directing air into the combustion chamber when the scoopis in operative position, and means for locking the scoop in extendedposition.

2. The invention recited in claim 1 and further including a blowout doorat the inner end of the inlet wall.

3. The invention recited in claim 1,

including additionally a leading edge element hingedly connected to thescoop body.

4. The invention as recited in claim 1,

wherein the means for slidably connecting the scoop body with thevehicle comprises sheaths formed in the vehicle body at each side of theinlet wall,

and guides on the scoop body and slidable in the sheaths.

5. The invention as recited in claim 4,

including means for engaging the ramp for moving the ramp into alignmentwith the inlet wall as the scoop is moved to operative position.

6. The invention as recited in claim 5,

wherein said ramp moving means includes a groove on the rear end of theramp, said groove defining a rolled portion and a lip, and an open endedslot in each of the guides near its rear end, said slots receiving saidrolled portion therein.

7. The invention as recited in claim 1,

wherein the scoop body comprises a leading edge element and a body platehingedly connected to the leading edge element,

said scoop body lying with a portion of said leading edge element inengagement with said ramp when thescoop is 1 in inoperative position,thus providing a smooth aerodynamic surface for said scoop.

8. The invention as recited in claim 1,

wherein the locking means comprises tracks on the vehicle and havinggrooves terminating at corresponding forward ends in locking ports,

locking elements carried by the scoop and having portions movable fromthe grooves into the locking ports,

and springs on the elements and cooperating with a wall of each of thegrooves for moving said elements out of alignment with said grooves,whereby said scoop will be prevented from moving into inoperativeposition.

9. The invention as recited in claim 1,

wherein the locking means comprises tracks on the vehicle and havingsaid grooves terminating at corresponding forward ends in locking ports,

side members on the scoop body and having openings.

grooves for moving the elements out of alignment with said grooves. 10.The invention as recited in claim 5, wherein the ramp engaging meanscomprises a spring on the vehicle and engaging said ramp.

i i i l

1. In an aerial vehicle having a combustion chamber, an air scoopcomprising; an inlet wall, a movable ramp mounted to cooperate with theinlet wall, a scoop body, means slidably connecting the scoop body tothe vehicle, said air scoop being movable from an inoperative positionlying adjacent the vehicle to an operative position extending from thevehicle, said scoop body, said ramp and said inlet wall cooperating todefine an air inlet for directing air into the combustion chamber whenthe scoop is in operative position, and means for locking the scoop inextended position.
 2. The invention recited in claim 1 and furtherincluding a blowout door at the inner end of the inlet wall.
 3. Theinvention recited in claim 1, including additionally a leading edgeelement hingedly connected to the scoop body.
 4. The invention asrecited in claim 1, wherein the means for slidably connecting the scoopbody with the vehicle comprises sheaths formed in the vehicle body ateach side of the inlet wall, and guides on the scoop body and slidableIn the sheaths.
 5. The invention as recited in claim 4, including meansfor engaging the ramp for moving the ramp into alignment with the inletwall as the scoop is moved to operative position.
 6. The invention asrecited in claim 5, wherein said ramp moving means includes a groove onthe rear end of the ramp, said groove defining a rolled portion and alip, and an open ended slot in each of the guides near its rear end,said slots receiving said rolled portion therein.
 7. The invention asrecited in claim 1, wherein the scoop body comprises a leading edgeelement and a body plate hingedly connected to the leading edge element,said scoop body lying with a portion of said leading edge element inengagement with said ramp when the scoop is in inoperative position,thus providing a smooth aerodynamic surface for said scoop.
 8. Theinvention as recited in claim 1, wherein the locking means comprisestracks on the vehicle and having grooves terminating at correspondingforward ends in locking ports, locking elements carried by the scoop andhaving portions movable from the grooves into the locking ports, andsprings on the elements and cooperating with a wall of each of thegrooves for moving said elements out of alignment with said grooves,whereby said scoop will be prevented from moving into inoperativeposition.
 9. The invention as recited in claim 1, wherein the lockingmeans comprises tracks on the vehicle and having said groovesterminating at corresponding forward ends in locking ports, side memberson the scoop body and having openings, locking discs in the openings andhaving locking elements extending into the grooves, and springs on thelocking elements, said locking elements being slidably from the groovesinto the locking ports when the scoop is moved fully forward andoutward, said springs cooperating with corresponding walls of thegrooves for moving the elements out of alignment with said grooves. 10.The invention as recited in claim 5, wherein the ramp engaging meanscomprises a spring on the vehicle and engaging said ramp.